NSDate detection with NSDataDetector

问题

I tried to get a NSDate from a NSString with UNKNOWN format, So I wrote a function like below

-(void)dateFromString:(NSString*)string {

    NSError *error = NULL;
    NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:(NSTextCheckingTypes)NSTextCheckingTypeDate error:&error];

    NSArray *matches = [detector matchesInString:string
                                         options:0
                                           range:NSMakeRange(0, [string length])];

    NSLocale* currentLoc = [NSLocale currentLocale];
    for (NSTextCheckingResult *match in matches) {
        if ([match resultType] == NSTextCheckingTypeDate) {
            NSLog(@"Date : %@", [[match date] descriptionWithLocale:currentLoc]);
        }
    }
}

It works well except for one place.

If I invoke

[self dateFromString:@"6/12"];

It prints

Date : Thursday, June 12, 2014 at 12:00:00 PM Australian Eastern Standard Time

At the same time if I call

[self dateFromString:@"13/12"];

it prints

Date : Friday, December 13, 2013 at 12:00:00 PM Australian Eastern Daylight Time

Basically, I want the function to behave consistent. Since I live in Australia, it should have returned December 6 for the first execution. Second call result is correct.

What am I doing wrong here?

回答1:

Actually, the method I wrote works really well :). Unfortunately, the Region Format in my test phone was set to US and was never set back to Australia : My bad..

@joiningss : Throw some random formatted date string to that methods and you will be amazed, how apple has made it easy for developers. Anyway, thank you so much.

@mrt,Chavda&Greg : Thanks a lot guys. I really appreciate your help.

回答2:

You have to use NSDateFormatter. Try replace your if statement with:

if ([match resultType] == NSTextCheckingTypeDate) {
   NSDate *dateAfter = [match date];
   NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
   [dateFormatter setDateFormat:@"yyyy-MM-dd 'at' HH:mm"];
   NSString *formattedDateString = [dateFormatter stringFromDate:dateAfter];
   NSLog(@"After: %@", formattedDateString);
}

If you want to display it in different format you have to change this line to required format:

[dateFormatter setDateFormat:@"yyyy-MM-dd 'at' HH:mm"];

If you want it to match your first example change it to:

[dateFormatter setDateFormat:@"EEEE, MMMM dd, yyyy 'at' HH:mm:ss a zzzz"];

来源：https://stackoverflow.com/questions/20418863/nsdate-detection-with-nsdatadetector

标签

ios

objective-c

nsdate

nsregularexpression

nsdatadetector